[dpdk-dev] [PATCH v2] net/virtio: fix rxq intr config fails using vfio-pci

Tan, Jianfeng jianfeng.tan at intel.com
Wed Nov 8 14:52:55 CET 2017


Hi Zhiyong,


On 11/8/2017 7:03 PM, Zhiyong Yang wrote:
> When running l3fwd-power to test virtio rxq interrupt using vfio
> pci noiommu mode, startup fails. In the function virtio_read_caps,
> the code if (flags & PCI_MSIX_ENABLE) intends to double check
> if vfio msix is enabled or not. However, it is not enable at that
> stage. So use_msix is assigned to "0", not "1", which causes the
> failure of configuring rxq intr in l3fwd-power.
> This patch adds the function vtpci_msix_detect to detect the status
> of msix when interrupt changes happen.
> In the meanwhile, virtio_intr_enable/disable are introduced to wrap
> rte_intr_enable/disable to enhance the ability to detect msix. Only
> support and enable msix can assign "1" to use_msix.

Should be "2". Better to use macro here.

>
> Fixes: cb482cb3a305 ("net/virtio: fix MAC address read")
> Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>
> ---
>   drivers/net/virtio/virtio_ethdev.c | 64 +++++++++++++++++++++++++++++++++-----
>   drivers/net/virtio/virtio_pci.c    | 42 +++++++++++++++++++++++++
>   drivers/net/virtio/virtio_pci.h    |  5 +++
>   3 files changed, 104 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index d2576d5e0..525cfa06c 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -97,6 +97,9 @@ static void virtio_mac_addr_remove(struct rte_eth_dev *dev, uint32_t index);
>   static void virtio_mac_addr_set(struct rte_eth_dev *dev,
>   				struct ether_addr *mac_addr);
>   
> +static int virtio_intr_enable(struct rte_eth_dev *dev);
> +static int virtio_intr_disable(struct rte_eth_dev *dev);
> +
>   static int virtio_dev_queue_stats_mapping_set(
>   	struct rte_eth_dev *eth_dev,
>   	uint16_t queue_id,
> @@ -618,7 +621,7 @@ virtio_dev_close(struct rte_eth_dev *dev)
>   		virtio_queues_unbind_intr(dev);
>   
>   	if (intr_conf->lsc || intr_conf->rxq) {
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
>   		rte_intr_efd_disable(dev->intr_handle);
>   		rte_free(dev->intr_handle->intr_vec);
>   		dev->intr_handle->intr_vec = NULL;
> @@ -1160,6 +1163,44 @@ virtio_vlan_filter_set(struct rte_eth_dev *dev, uint16_t vlan_id, int on)
>   }
>   
>   static int
> +virtio_intr_enable(struct rte_eth_dev *dev)
> +{
> +	struct virtio_hw *hw = dev->data->dev_private;
> +	int msix_detect;

As I don't think we need to return a value except 0, 1, 2 as my comment 
at the end, so I suppose we just:

     hw->use_msix = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));

> +
> +	if (rte_intr_enable(dev->intr_handle) < 0)
> +		return -1;
> +
> +	msix_detect = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));

This breaks virtio_user. Need to add a check before this line.

> +	if (msix_detect < 0)
> +		return -1;
> +	else if (msix_detect == SUPPORT_MSIX_STATUS_ENABLED)
> +		hw->use_msix = 1;
> +	else
> +		hw->use_msix = 0;
> +	return 0;
> +}
> +
> +static int
> +virtio_intr_disable(struct rte_eth_dev *dev)
> +{
> +	struct virtio_hw *hw = dev->data->dev_private;
> +	int msix_detect;
> +
> +	if (rte_intr_disable(dev->intr_handle) < 0)
> +		return -1;
> +
> +	msix_detect = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));

Ditto.

> +	if (msix_detect < 0)
> +		return -1;
> +	else if (msix_detect == SUPPORT_MSIX_STATUS_ENABLED)
> +		hw->use_msix = 1;
> +	else
> +		hw->use_msix = 0;
> +	return 0;
> +}
> +
> +static int
>   virtio_negotiate_features(struct virtio_hw *hw, uint64_t req_features)
>   {
>   	uint64_t host_features;
> @@ -1228,7 +1269,7 @@ virtio_interrupt_handler(void *param)
>   	isr = vtpci_isr(hw);
>   	PMD_DRV_LOG(INFO, "interrupt status = %#x", isr);
>   
> -	if (rte_intr_enable(dev->intr_handle) < 0)
> +	if (virtio_intr_enable(dev) < 0)
>   		PMD_DRV_LOG(ERR, "interrupt enable failed");
>   
>   	if (isr & VIRTIO_PCI_ISR_CONFIG) {
> @@ -1348,7 +1389,7 @@ virtio_configure_intr(struct rte_eth_dev *dev)
>   	 * to change the config size from 20 to 24, or VIRTIO_MSI_QUEUE_VECTOR
>   	 * (22) will be ignored.
>   	 */
> -	if (rte_intr_enable(dev->intr_handle) < 0) {
> +	if (virtio_intr_enable(dev) < 0) {
>   		PMD_DRV_LOG(ERR, "interrupt enable failed");
>   		return -1;
>   	}
> @@ -1370,7 +1411,15 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
>   	struct virtio_net_config local_config;
>   	struct rte_pci_device *pci_dev = NULL;
>   	int ret;
> +	int msix_detect;
>   
> +	msix_detect = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(eth_dev));
> +	if (msix_detect < 0)
> +		return -1;
> +	else if (msix_detect == SUPPORT_MSIX_STATUS_ENABLED)
> +		hw->use_msix = 1;
> +	else
> +		hw->use_msix = 0;

Ditto, we directly assign return value to hw->use_msix.

>   	/* Reset the device although not necessary at startup */
>   	vtpci_reset(hw);
>   
> @@ -1388,7 +1437,8 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
>   	}
>   
>   	/* If host does not support both status and MSI-X then disable LSC */
> -	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) && hw->use_msix)
> +	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) &&
> +	    (msix_detect >= SUPPORT_MSIX_STATUS_DISABLED))

!= should be better than >= here.

>   		eth_dev->data->dev_flags |= RTE_ETH_DEV_INTR_LSC;
>   	else
>   		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
> @@ -1801,9 +1851,9 @@ virtio_dev_start(struct rte_eth_dev *dev)
>   	 */
>   	if (dev->data->dev_conf.intr_conf.lsc ||
>   	    dev->data->dev_conf.intr_conf.rxq) {
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
>   
> -		if (rte_intr_enable(dev->intr_handle) < 0) {
> +		if (virtio_intr_enable(dev) < 0) {
>   			PMD_DRV_LOG(ERR, "interrupt enable failed");
>   			return -EIO;
>   		}
> @@ -1912,7 +1962,7 @@ virtio_dev_stop(struct rte_eth_dev *dev)
>   	PMD_INIT_LOG(DEBUG, "stop");
>   
>   	if (intr_conf->lsc || intr_conf->rxq)
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
>   
>   	hw->started = 0;
>   	memset(&link, 0, sizeof(link));
> diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
> index 55b717c03..a73b41765 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -710,3 +710,45 @@ vtpci_init(struct rte_pci_device *dev, struct virtio_hw *hw)
>   
>   	return 0;
>   }
> +
> +/* Return -1 fails to detect msix.

I don't think we need to return -1. We can treat the error as msix not 
supported.

> + * Return 0 (NO_SUPPORT_MSIX) don't support msix.
> + * Return 1 (SUPPORT_MSIX_STATUS_DISABLED) support msix, status: disabled.
> + * Return 2 (SUPPORT_MSIX_STATUS_ENABLED) sppport msix, status: enabled.
> + */
> +
> +int
> +vtpci_msix_detect(struct rte_pci_device *dev)
> +{
> +	uint8_t pos;
> +	struct virtio_pci_cap cap;
> +	int ret;
> +
> +	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
> +	if (ret < 0) {
> +		PMD_INIT_LOG(DEBUG, "failed to read pci capability list");
> +		return -1;

I suppose we can return NO_SUPPORT_MSIX here.

> +	}
> +
> +	while (pos) {
> +		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
> +		if (ret < 0) {
> +			PMD_INIT_LOG(ERR,
> +				"failed to read pci cap at pos: %x", pos);
> +			break;
> +		}
> +
> +		if (cap.cap_vndr == PCI_CAP_ID_MSIX) {
> +			uint16_t flags = ((uint16_t *)&cap)[1];
> +
> +			if (flags & PCI_MSIX_ENABLE)
> +				return SUPPORT_MSIX_STATUS_ENABLED;
> +			else
> +				return SUPPORT_MSIX_STATUS_DISABLED;
> +		}
> +
> +		pos = cap.cap_next;
> +	}
> +
> +	return NO_SUPPORT_MSIX;
> +}
> diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> index 36d452c06..401afc7f9 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -314,6 +314,10 @@ struct virtio_net_config {
>   /* The alignment to use between consumer and producer parts of vring. */
>   #define VIRTIO_PCI_VRING_ALIGN 4096
>   
> +#define NO_SUPPORT_MSIX 0
> +#define SUPPORT_MSIX_STATUS_DISABLED 1
> +#define SUPPORT_MSIX_STATUS_ENABLED 2

Maybe we refine the name as:
VIRTIO_MSIX_NONE
VIRTIO_MSIX_DISABLED
VIRTIO_MSIX_ENABLED

> +
>   static inline int
>   vtpci_with_feature(struct virtio_hw *hw, uint64_t bit)
>   {
> @@ -325,6 +329,7 @@ vtpci_with_feature(struct virtio_hw *hw, uint64_t bit)
>    */
>   int vtpci_init(struct rte_pci_device *dev, struct virtio_hw *hw);
>   void vtpci_reset(struct virtio_hw *);
> +int vtpci_msix_detect(struct rte_pci_device *dev);
>   
>   void vtpci_reinit_complete(struct virtio_hw *);
>   



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